WASHINGTON (AP) _ Forty percent or more of Americans believe flying saucers are real, that rockets change the weather and certain numbers bring good luck, says a new poll whose author suggests the results show a technologically confused society.

Those survey results and others indicate that while some of the American public is somewhat informed on technological issues, ''a substantial portion is not well informed in these areas,'' Jon D. Miller, director of the Public Opinion Laboratory at Northern Illinois University, said Thursday.

For example, he said his poll, sponsored by the National Science Foundation, found 95 percent of Americans agreeing with the statement that ''smoking causes serious health problems'' - a contention the medical profession strongly supports.

However, 75 percent also agreed with a statement that ''there are good ways of treating sickness that medical science does not recognize.''

Of the second finding, Miller said in a telephone interview, ''It is not clear whether this result is an endorsement of folk medicine ... or a vote of no confidence in the medical profession. Whatever its origins, it appears inconsistent with the idea of technological literacy.''

Such literacy - or perhaps illiteracy in some cases - was the focus of a weekend conference beginning today in Baltimore. The poll also was released in Washington.

An announcement of the conference said, ''Evidence abounds that we are graduating students who are unprepared and unable to grasp even day-to-day issues - the technical content of issues ranging from the safety of contraceptive devices or nutrition to robotics, gene-splicing or the recent explosion of the space shuttle Challenger.''

Other findings in Miller's poll, conducted among 2,000 randomly selected adults late last year, indicated:

-Forty-three percent agreed with the statement that ''it is likely that some of the unidentified flying objects that have been reported are really space vehicles from other civilizations.''

-Forty-one percent agreed that ''rocket launchings and other space activities have caused changes in our weather.''

With 11 percent and 12 percent, respectively, saying they weren't sure about the two statements, that left less than 50 percent disagreeing in both cases. Miller said that suggests ''a substantial level of confusion between real or likely technologies and fictional technologies.''

On another statement, 40 percent agreed that ''some numbers are especially lucky for some people.''

However, on another, only 20 percent agreed with the statement that ''it is not wise to plan ahead because many things turn out to be a matter of good or bad luck anyway.''

''While it is somewhat comforting to find that a majority of the American people reject luck as the driving force of their lives and of society, it is important to remember that each percentage point in a national survey represents 1.7 million people,'' Miller said in an accompanying text.

''In real numbers, these results indicate that approximately 37 million Americans eschew planning for the future and that almost 75 million believe in lucky numbers,'' he said. ''While these numbers may be good news for the people who run lotteries, they are not a positive reflection on the technological literacy of our society.''

In another section of the survey, people were asked to rate their own understanding of what Miller called ''some of the basic terms needed to communicate about technological issues.''

Eighty-two percent said they had a clear or general understanding of radiation, 67 percent felt they had such understanding of how a telephone works, 57 percent of computer software and 49 percent of economic gross national product. The rest said they had little understanding of the terms.

The study was conducted by telephone with each respondent interviewed for about 30 minutes, Miller said. He gave no expected margin of sampling error.

The Baltimore conference, organized by Pennsylvania State University with support from the National Science Foundation, was co-sponsored by the American Association for the Advancement of Science and the National Science Teachers Association, among others, the announcement said.